1. Field of the Invention
The present invention relates to a method of and an apparatus for automatically attaching top stops to a longitudinally gapped, continuous slide fastener chain at ends of longitudinally spaced rows of coupling elements with sliders slidably mounted thereon, respectively.
2. Prior Art
For applying top stops to a continuous slide fastener chain, it has been customary to move upwardly a tongue-shaped chain spreader between stringer tapes adjacent to ends of rows of coupling elements, and then attach the top stops to the ends of coupling element rows on the stringer tapes spaced laterally from each other. The chain spreader tends to loosen and lift confronting edges of the tapes as they are spread apart. Since there has been no mechanism for holding the tape edges stably down against lower dies, the chain spreader has caused the tape edges to buckle up. In the past, top stops have often been merely applied to the tape edges without checking them for the way in which they are supported. The tongue-shaped chain spreader as it spreads the chain is held in point-to-point contact with coupling elements, so that the chain spreader fails to guide and support the ends of rows of coupling elements stably along the direction of travel of the slide fastener chain. With the above prior process, therefore, top stops cannot be reliably and accurately applied to the edges of the stringer tapes, and the attaching operation cannot be speeded up.
In an effort to eliminate the prior difficulties, the applicant has proposed a method of and an apparatus for automatically attaching top stops to a longitudinally gapped, continuous slide fastener chain with sliders slidably mounted thereon. According to the proposed arrangement, confronting edges of stringer tapes where top stops are to be applied are kept parallel to each other with the tapes being stably placed in position by a tape presser. Top stops can automatically be attached to a slide fastener chain reliably and in good condition at an increased rate of attachment. In operation, the feed of the chain is stopped at the detection of a slider positioned on a pair of coupling element rows and spaced a distance from the ends of the coupling element rows where top stops are to be attached, in the direction in which the chain travels. Then, a chain stopper, inserted in a gap in the chain and held against a bottom stop thereon, is actuated to move the chain until the ends of the coupling element rows are positioned on clinching dies. This positioning method is disadvantageous in that varying lengths of spaces or gaps in the chain cause incorrect positioning of the ends of the coupling element rows. Another problem is that a detector, for detecting the chain stopper as pushed by the bottom stop when the chain is fed a constant interval, cannot easily be adjusted in position to meet different space lengths.